PDF Ebook Blood Pressure Variability in Neonates
In a neonatal intensive care unit, care is given to very ill neonates, most of whom are prematures. In the prognosis and treatment of such neonates, both lung and brain conditions play an important role. The treatment of immature lungs has been significantly improved by a routine use of surfactant. The assessment of the brain function remains an important issue.
The patients are continuously monitored. Treatment is evaluated using data recordings from the monitors (vital signs) and intermittently obtained values (blood gases, weight, and defecation). The vital signs, however, are often disturbed by movement artefacts and cannot be measured as easily as in adult intensive care conditions. The evaluation of the condition of the patient and his or her treatment needs a reliable vital signs data set and effective use of the small number of signals measured. A physiological-data acquisition system, capable of real-time artefact reduction and analysis, combining data, and archiving of the measurements, is necessary to optimise the information on the condition of the patient.
Such an acquisition system would allow - for example - the assessment of additional information present in the invasive arterial blood pressure signal. In this thesis a strategy to quantify the low frequency blood pressure components, related to lung mechanics, brain and nervous functions, will be described. Two applications, built on this strategy and made for use in neonatal practice, will be presented and evaluated.
Contents
1. INTRODUCTION
- 1.1 DEVELOPMENT OF AN INFORMATION SYSTEM
1.2 FOCUS ON BLOOD PRESSURE
1.3 OBJECTIVES
1.4 OUTLINE
2. PHYSIOLOGY
- 2.1 THE NERVOUS SYSTEM
- 2.1.1 Parasympathetic and sympathetic nervous system
2.2 CARDIOVASCULAR REGULATION
- 2.2.1 Inventory of interactions involving the cardiovascular system
2.2.2 Influences on the blood pressure
3. DATA ACQUISITION SYSTEM
- 3.1 DATA ACQUISITION SYSTEM REQUIREMENTS
3.2 SET UP OF THE MEASUREMENT SYSTEM
- 3.2.1 acquisition
3.2.2 processing, analysis, and reduction
3.2.3 Display
3.2.4 archiving and administration
3.3 DEVELOPMENT
3.4 CONCLUSION
4. MEASUREMENT OF THE SIGNALS
- 4.1 BLOOD PRESSURE MEASUREMENTS
- 4.1.1 physiology
4.1.2 non-invasive blood pressure measurement techniques
4.1.3 invasive blood pressure measurements
4.2 HEARTRATE MEASUREMENTS
- 4.2.1 acquisition
4.2.2 determination of the moment of heartbeat
4.2.3 conclusion
4.3 RESPIRATION MEASUREMENTS
- 4.3.1 thoracic impedance measurements
4.3.2 measurements by a thermistor
4.3.3 detection of apnoea periods
5. FREQUENCY DOMAIN ANALYSIS OF THE INVASIVE BLOOD PRESSURE SIGNAL
- 5.1 INTRODUCTION
5.2 DISCRETE FOURIER TRANSFORMS
- 5.2.1 Common distortions of the discrete Fourier transform
5.2.2 Accuracy of estimated spectral components
5.2.3 Linearity
5.3 NON - EQUIDISTANT SAMPLING
- 5.3.1 Short introduction to the IPFM model
5.3.2 Frequency analysis of non-equidistantly sampled signals
5.3.3 Direct Blood pressure filtering method (BPF)
5.4 REAL-TIME ANALYSIS IN PRACTICE
- 5.4.1 Digital Fourier Transforms in practice
5.4.2 Evaluation of neonatal data
5.5 CONCLUSIONS
6. CLINICAL APPLICATIONS
- 6.1 CONTINUOUS SPECTRAL AMPLITUDE ESTIMATES
- 6.1.1 Methods
6.1.2 Results
6.1.3 Discussion
6.2 CORRELATIONS BETWEEN BLOOD PRESSURE AND HEARTRATE
- 6.2.1 Introduction
6.2.2 Methods
6.2.3 Results
6.2.4 Discussion
7. FINAL DISCUSSION
- 7.1 DATA ACQUISITION SYSTEM
7.2 MEASUREMENT OF THE SIGNALS
7.3 FREQUENCY DOMAIN ANALYSIS OF THE INVASIVE ARTERIAL BLOOD PRESSURE SIGNAL
- 7.3.1 Aliasing
7.3.2 Spectral leakage
7.3.3 Spectral equidistancy
7.3.4 Stationarity
7.3.5 beat-to-beat values versus the full sampled signal
7.4 CLINICAL APPLICATIONS
SUMMARY
SAMENVATTING
DANKWOORD
CURRICULUM VITAE
Posted in :
